Hazard Flashing Warning Light Unit problems of the 2006 Jeep Grand Cherokee

While driving in normal dry conditions this past evening unexpectedly all my interior gauges and dash electronics started flickering on and off to include the radio, hazard lights and everything inside. At the same time I realized I was also loosing my exterior headlights and also brake control because my car was essentially running but with no electronics. It started making a weird grinding pulsating noise that would accompany the flickering lights. This forced me to exit the road at a gas station. It then stopped and I began driving again only to have it resume shortly. Thankfully I was close to my destination and was able to shut the vehicle off for the night. This has happened occasionally in the past couple months during the day but this is my first night experience. I thought it was just a glitch but it is definitely getting worse and has become regular. The next morning I was able start and drive my vehicle to work and it repeated this behavior a couple more times. At days end I went to leave and now my Jeep won't start and hasn't for two days. All the electronics come on but when I turn the key it just clicks. I also had this problem in the past but when my mechanic looked at it he was unable to duplicate the problem.